Host plant stimuli effects on survival and duration of dormancy of Rhagoletis zoqui, Rhagoletis completa (Diptera: Tephritidae) and associated parasitoids.

Tephritid fruit flies in the genus Rhagoletis bridge between predictable periods of fruit availability by becoming dormant. To cope with acyclic unpredictable events (e.g., frost, mast seeding, etc), a proportion of the population can undergo prolonged dormancy. In the case of walnut infesting Rhagoletis, host plant-derived cues such as juglone soil concentration vary seasonally in predictable patterns. Here, we examined the effects of host plant parts and derived compounds on emergence rates and dormancy duration of Rhagoletis completa (Cresson), Rhagoletis zoqui (Bush) (Diptera: Tephritidae), and associated parasitoids. Pupae of both species were exposed to walnut leaves, fruit, or fruit and leaves and compared to a control. In a second experiment, R. zoqui were exposed to 10 mg l-1 of juglone applied to pupation medium during four consecutive 4-week time periods under variable combinations of temperature and frequency of exposure. Overall, the presence of fruit resulted in greater overwintering survival of R. completa but had no effect on the duration of dormancy of either fly species. Application of juglone over two consecutive periods produced greater mortality of R. zoqui than the control. Three parasitoid species emerged from R. completa and one from R. zoqui. Duration of dormancy for parasitoids was longer than that of fly hosts. Regardless of treatment, 13.3-18.4% of R. completa pupae and 1.3-2.8% R. zoqui engaged in prolonged (>year) dormancy. Our results indicate that host plant derived cues have little or no effect on survival and duration of dormancy of walnut infesting Rhagoletis, and at the tested concentration juglone is toxic to R. zoqui pupae. Testing the effect of juglone at lower concentrations is necessary to rule out its role as an environmental cue for regulation of dormancy. So far, host plant fruiting phenology appears to play a greater role than host plant derived cues in selecting for fly eclosion times.

Differential Response to Photoperiod by Diverging Rhagoletis pomonella (Diptera: Tephritidae) Populations Exploiting Host Plants with Different Fruiting Phenology.

Photoperiod has been found to influence the proportion of non-dormant individuals and the duration of dormancy among North American populations of Rhagoletis pomonella (Walsh) (Diptera: Tephritidae). In particular, long days combined with high temperatures can produce a 100% non-dormant generation. There are several genetically distinct populations of R. pomonella in the highlands of Mexico, two of which occur at the same latitude, at different elevations, that exploit hawthorn plants with different fruiting phenology (early (summer-fall) and late (winter)). Flies exploiting such hosts might use day length in different ways as a cue to match adult emergence with fruit availability. Here, we compared responses of pupae from two Mexican populations of R. pomonella to a 12/12 L/D photoperiod, a long-day photoperiod 17/7 L/D, and continuous illumination. Experiments were performed under warm conditions (27°C). Day length had no effect on the proportion of adults emerged from the early-fruiting hawthorn population, while pupae extracted from late-fruiting hawthorns and exposed to long days emerged as adults in lower proportions and engaged in prolonged dormancy in greater proportions than those exposed to a short day. Photoperiod had no effect on the proportion from both Mexican populations foregoing dormancy. Dormancy duration was affected by photoperiod and was longer than previous reports for North American populations. Host plant fruiting phenology may be the driver of these differences. These findings, coupled with previous reports of genetic and biological differences, suggest that the Eje Volcanico Trans-Mexicano R. pomonella population may actually be a distinct species.

The effect of winter length on duration of dormancy and survival of specialized herbivorous Rhagoletis fruit flies from high elevation environments with acyclic climatic variability.

Dormancy can be defined as a state of suppressed development allowing insects to cope with adverse conditions and plant phenology. Among specialized herbivorous insects exploiting seasonal resources, diapause frequently evolves as a strategy to adjust to predictable plant seasonal cycles. To cope with acyclic and unpredictable climatic events, it has been found for some insects that a proportion of the population undergoes prolonged dormancy. We compared the response of three species in the Rhagoletis cingulata species group exploiting plants differing in fruiting phenology from environments varying in frequency and timing of acyclic climatic catastrophic events (frost during flowering and fruit set) and varying also in the time of the onset of the rainy season. Small proportions (10 months), and large proportions of pupae died without emerging as adults. The number of days elapsed from the end of artificial winter and adult eclosion was longer for R. cingulata exploiting late fruiting Prunus serotina in Northeastern Mexico than for flies recovered from earlier fruiting plants in the central Altiplano. Rhagoletis turpiniae and northeastern R. cingulata pupae suffered high proportions of parasitism. Large proportions of R. cingulata from central Mexico engaging in prolonged dormancy may be explained by the fact that flowering and fruit set for its host, P. serotina var capuli, driven by the timing of maximum precipitation, matches a period of highest probability of frost often resulting in large areas with fruitless trees at unpredictable time intervals. As a consequence of differences in host plant fruiting phenology, central and northeastern Mexican R. cingulata were found to be allochronically isolated. Prolonged dormancy may have resulted in escape from parasitism.

Benzalkonium Chloride Provides Remarkable Stability to Liquid Protein Lures for Trapping Anastrepha obliqua (Diptera: Tephritidae).

Hydrolyzed protein lures are widely used to monitor fruit fly pests but are rapidly degraded by microbial activity and must be replaced frequently. To improve the stability of lures, the quaternary ammonium biocide, benzalkonium chloride (BC), was evaluated in mixtures with two hydrolyzed proteins commonly used to monitor Anastrepha spp. The mean number of Anastrepha obliqua adults captured during six consecutive weeks using Captor + borax with the addition of 240 mg BC/liter, not renewed during the test, was similar to Captor + borax that was replaced at weekly intervals and was more effective than Captor + borax without BC. Numbers of A. obliqua flies captured in 30% CeraTrap diluted in water containing 240 mg BC/liter were similar to those caught in traps baited with Captor + borax or 30% CeraTrap without BC in the first 9 d of evaluation but was significantly more effective than both lures after 56 d. After >2 mo of use, 30% CeraTrap containing 240 mg BC/liter remained as effective as newly prepared 30% CeraTrap. The addition of BC to lures reduced surface tension of liquid lures by ~40-50%. However, when BC was increased to 720 mg BC/liter, only a small additional reduction in surface tension was observed and higher concentrations of BC did not increase capture rates. These findings could contribute to reduced costs for trapping networks and the development of long-lasting formulations of liquid protein lures for bait stations and mass-trapping targeted at major tephritid pests.

Development of a Low-Cost and Effective Trapping Device for Apple Maggot Fly (Diptera: Tephritidae) Monitoring and Control in Mexican Commercial Hawthorn Groves.

Few efforts have been made in Mexico to monitor Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) in commercial hawthorn (Crataegus spp.) crops. Therefore, the main objectives of this study were to evaluate infestation levels of R. pomonella in feral and commercial Mexican hawthorn and to assess the efficacy of different trap-lure combinations to monitor the pest. Wild hawthorn was more infested than commercially grown hawthorn at the sample site. No differences among four commercial baits (Biolure, ammonium carbonate, CeraTrap, and Captor + borax) were detected when used in combination with a yellow sticky gel (SG) adherent trap under field conditions. However, liquid lures elicited a slightly higher, although not statistically different, capture. Cage experiments in the laboratory revealed that flies tended to land more often on the upper and middle than lower-bottom part of polyethylene (PET) bottle traps with color circles. Among red, orange, green, and yellow circles attached to a bottle trap, only yellow circles improved fly captures compared with a colorless trap. A PET bottle trap with a red circle over a yellow background captured more flies than a similar trap with yellow circles. An SG adherent yellow panel trap baited with ammonium carbonate was superior to the improved PET bottle trap (red over a yellow background) baited with different liquid proteins, but a higher proportion of females and no differences in fly detection were measured in PET traps baited with protein lures. These trials open the door for future research into development of a conventional nonadherent trap to monitor or control R. pomonella.

Genetic and Biological Characterization of Four Nucleopolyhedrovirus Isolates Collected in Mexico for the Control of Spodoptera exigua (Lepidoptera: Noctuidae).

This study describes four multiple nucleocapsid nucleopolyhedrovirus isolates recovered from infected larvae of beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on crops in two different geographical regions of Mexico. Molecular and biological characterization was compared with characterized S. exigua multiple nucleopolyhedrovirus (SeMNPV) isolates from the United States (SeUS1 and SeUS2) and Spain (SeSP2). Restriction endonuclease analysis of viral DNA confirmed that all Mexican isolates were SeMNPV isolates, but molecular differences between the Mexican and the reference isolates were detected using PCR combined with restriction fragment length polymorphism (RFLP). Amplification of the variable region V01 combined with RFLP distinguished the two Mexican isolates, SeSLP6 and SeSIN6. BglII digestions showed that the majority of the isolates contained submolar bands, indicating the presence of genetic heterogeneity. Amplification of the variable regions V04 and V05 distinguished between American and the Spanish isolates. Biological characterization was performed against two laboratory colonies of S. exigua, one from Mexico, and another from Switzerland. Insects from the Mexican colony were less susceptible to infection than insects from Se-Swiss colony. In the Se-Mex colony, SeSP2 was the most pathogenic isolate followed by SeSIN6, although their virulence was similar to most of the isolates tested. In Se-Swiss colony, similar LD50 values were observed for the five isolates, although the virulence was higher for the SeSLP6 isolate, which also had the highest OB (occlusion body) yield. We conclude that the Mexican isolates SeSIN6 and SeSLP6 possess insecticidal traits of value for the development of biopesticides for the control of populations of S. exigua.

The effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology.

Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (<1%) of R. pomonella, R. turpiniae and R. zoqui completed development without becoming dormant, while in the case of R. solanophaga the majority of the population emerged after development within 40 days of pupation. Also, a large proportion of braconid parasitoids infesting Rhagoletis eggs and larvae emerged as adults without becoming dormant. Greatest survival after artificial winter was obtained for R. pomonella (50-60%) and R. zoqui (30%) after only four weeks at 5°C (a third of the time reported for studies on northern R. pomonella), while R. turpiniae, under identical environmental conditions experienced low adult emergence, and highest survival (11%) was recorded for flies exposed to 5°C during 10 and 12 weeks. For R. pomonella, there was a strong positive relationship between winter length and time to post-winter adult eclosion that was not observed for R. zoqui. In sum, for R. pomonella, mild winters in highland subtropical areas appear to select for flies better able to withstand longer periods of warm temperature before winter than flies exploiting late fruiting hosts and inhabiting northern latitudes. In the case of R. turpiniae and R. zoqui environmental cues such as fluctuations in humidity and/or different temperature thresholds (5°C) may play a more important role than winter length in life history regulation. Continuous host availability for R. solanophaga appears to have selected for non-diapausing flies. From an applied perspective our results are useful for handling flies in the laboratory to conduct research and suggest that non-diapausing strains of flies and parasitoids may be selected for SIT and innundative biological control programs.

Comparison of Hydrolyzed Protein Baits and Various Grape Juice Products as Attractants for Anastrepha Fruit Flies (Diptera: Tephritidae).

Mexican fruit flies, Anastrepha ludens (Loew; Diptera: Tephritidae), have traditionally been trapped in citrus orchards in Mexico using protein hydrolysates as bait. Recently, CeraTrap(®), an enzymatic hydrolyzed protein, has emerged as an effective lure for monitoring A. ludens at the orchard level and is currently being used by growers in the region of Veracruz. Several studies have revealed that grape juice is highly attractive to A. ludens, and recent work supports its potential use for regulation purposes. In our study, the attraction of A. ludens to different grape products was evaluated in citrus orchards and in comparison to other Anastrepha species in an area composed of mango and chicozapote orchards. Attraction to grape lures was compared with CeraTrap and the standard protein Captor +borax trap. In general, CeraTrap was more attractive than different commercial grape products in several experiments. Only Jumex, a commercial grape juice, did not differ significantly from CeraTrap in the capture of A. ludens males and females in a citrus crop. However, several drawbacks were detected when using Jumex grape juice: 1) higher tendency to capture males, 2) less selectivity against non-targeted insects, 3) higher capture of beneficial lacewings, and iv) the need to re-bait weekly owing to lower stability. In the area containing mango and chicozapote, CeraTrap was more attractive than Captor + borax for Anastrepha obliqua and Anastrepha serpentina, followed by grape juice products, which were the least attractive for these fruit fly species.

Economic and Highly Effective Trap-Lure Combination to Monitor the Mexican Fruit Fly (Diptera: Tephritidae) at the Orchard Level.

Monitoring population levels of the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), at the orchard level prior and during the fruit ripening period can result in significant savings in the costs of managing this pestiferous insect. Unfortunately, to date, no highly effective and economically viable trap is available to growers. To move toward this goal, trap-lure combinations were evaluated in trials performed in citrus orchards in Veracruz, Mexico. CeraTrap, an enzymatic hydrolyzed protein from pig intestinal mucose, was 3.6 times more attractive to A. ludens than the most commonly used bait of Captor (hydrolyzed protein and borax) when using Multilure traps. When several commercial traps were evaluated, the efficacy of a simple and inexpensive transparent polyethylene (PET) bottle with 10-mm lateral holes was similar to that of the costly Multilure trap when baited with CeraTrap and significantly more effective than a Multilure trap baited with Captor. PET bottles filled with Cera Trap, rebaited at 8-wk intervals, and tested in trials encompassing 72 ha of citrus groves, were significantly more effective than Multilure traps baited with Captor that need to be serviced weekly. In addition to this relevant finding, CeraTrap baited traps detected A. ludens at lower population densities and attracted a significantly higher number of flies at all densities when compared with Captor-baited traps. We conclude that CeraTrap represents a cost-effective and highly efficient bait that will enable us to pursue the goal of developing economic thresholds, a badly needed management tool for A. ludens.

[Hodgkin's disease. Our 9-year experience with the 1980 protocol]. / Enfermedad de Hodgkin. Nuestra experiencia de neuve años con el protocolo de 1980.

The purpose of this work was to evaluate the therapeutic results attained with our 1980 protocol for Hodgkin's disease. The usefulness of staging laparotomy was also analysed. Along a 9-year period, 94 patients were diagnosed (stages IA and IIA: 26 cases, IB, IIB and IIIA: 24 cases, and IIIB and IV: 44 cases). The complete remission (CR) rate, as a whole, was 85%; there were 14 relapses, of whom a new CR was attained in 9 instances. The overall actuarial survival is 64% at 47 months. The appearance of 3 cases of acute non-lymphoblastic leukaemia is noteworthy. Laparotomy induced changes of the patient's staging in 49% of cases (rise in 43% and descent in 6%). In account of this, laparotomy seems an adequate procedure in staging, although the criteria for selecting the patients who will undergo this, procedure should be perhaps restrictive.

[Non-Hodgkin's lymphoma in childhood. Review of 33 cases]. / Linfoma no Hodgkin infantil. Revisión de 33 casos.

A retrospective study was performed of 33 cases of non Hodgkin's lymphoma in children diagnosed in our hospital. The mean age was 10 years and there were 24 males and 9 females. The distribution, according to Rappaport's diagnostic classification, was: 11 undifferentiated lymphomas, 9 lymphoblastic lymphomas, 6 diffuse histiocytic lymphomas, and 7 cases of other types. Of the 33 patients, 23 had bulky disease (over 5 cm. in diameter). The mean serum LDH and uric acid values were, respectively, 537 (68-2021) and 6.0 (2.7-19). According to Murphy's staging system, the distribution of the cases was as follows: I (1), II (4), III (12), IV (16). Since this study spreads for a long period, several protocols have been used in the treatment of the group, but most patients received the LSA2-L2 regimen. Complete remission (CR) was achieved in 26 cases (78%), this being 100% of the lymphoblastic lymphomas. After a mean follow-up of 45 months, the actuarial survival is 48.1%, and the disease-free survival of patients attaining CR is 60.4%. The prognostic factors analysed, such as histologic type, stage, and serum LDH showed no statistical significance, probably due to the low number of cases studied.

[Burkitt's lymphoma. Report of six cases (author's transl)]. / Linfoma de Burkitt. Aportación de seis casos.

Authors report six cases on Burkitt's lymphoma seen during the last 18 months. In all of them a large ileocecal tumor was present and five of them had a bone marrow involvement. The ascitic fluid was positive in all cases. Three of the patients had a marked jaundice at diagnosis. The immunologic markers study on two of the cases, made evident that they belonged to type B. One of these two cases showed a component M in serum of the IgM type. As soon as chemotherapy started two of the cases showed marked metabolic disturbances. Three of the cases died and the three others remain free of disease for as long as two, 26 and 21 months. This report arises a comment epidemiologic importance of the increased frequency of Burkitt's lymphoma during the last months, as well as the clinic features of the six reported cases as compared to series published in non endemic areas on this topic.